1. Field of the Invention
This invention is related to an electronic clinical thermometer with a flexible structure, and in particular to one which comprises a flexible covering having a probing portion, and a hard stem having an appropriate length and connecting the metal probe to the distal end of the probing portion of the flexible covering, so that the probing portion will not break even if the probing portion is bent for measuring operation many times, thereby ensuring safety in use and wherein the flexible covering appropriately encloses the casing and has a waterproof push button, locating flange and embossed portion for turning on/off the switch when the flexible push button is depressed by the user and for making the clinical thermometer waterproof, appealing in appearance, facile to fabricate, easy to hold, simple to process, and low in cost. Further, the casing of the clinical thermometer may be made of transparent material and appropriately enclosed with a flexible covering for facilitating holding of the thermometer and providing a transparent window for viewing the temperature reading.
2. Description of the Related Art
Conventional electronic thermometers commonly have a hard casing formed from plastics and a metal probe at the tapered front end of the hard casing. Because the tapered front end of a conventional electronic thermometer is not flexible, the user must use the thermometer carefully, to prevent a break from occurring in the connection area between the casing and the metal probe. In order to eliminate this problem, electronic thermometers with a flexible probing structure have been developed. The flexible probing structure is generally made of rubber material so that the probe can be bent in use as required. However, these electronic thermometers suffer from drawbacks such as insufficient structural strength and being unsanitary. Furthermore, the conventional electronic thermometer is generally complicated in manufacture and expensive in cost.
FIGS. 1 and 2 show an electronic thermometer constructed according to Taiwan Patent Publication No. 495024 entitled “Improvement in the structure of a flexible electronic thermometer”. As illustrated, this electronic thermometer comprises a casing 40 having a probing portion 41 at the front section and a tubular member 42 formed of hard plastics and fitted in the interior of the front end of the probing portion 41, thereby enabling a metal sensor 43 to be fitted in the probing portion 41.
Referring to FIG. 3, when probing portion 41 of the casing 40 is curved for use in measuring temperatures, if the probing portion 41 is made of flexible material such as rubber, stress will be concentrated at the connection portion 46 between the tubular member 42 and the probing portion 41 because the tubular member 42 will apply a pressure to the flexible probing portion 41 thereby continually concentrating stress at the connection portion 46 after it has been bent a number of times, and therefore causing a tendency to break the connection portion 46. It is obvious that such a thermometer does not have sufficient strength in structure and is not safe in use.
Further, if the probing portion 41 is made of flexible material, particularly rubber, which is low in density, the probing portion 41 will have a rough surface which can easily become covered with dirt particles. It is extremely difficult to remove the particles from the rough surface thereby causing sanitary problems.
With further reference to FIGS. 1 and 2, the probing portion 41 is engaged only with the casing 40 of the thermometer (which is generally made of hard material) and does not enclose the casing 40 partially or wholly, so that the probing portion 41 is only connected to a portion of the front end of the casing 40. As a consequence, the connection area between the probing portion 41 and the casing 40 is too small to provide a sturdy engagement. Hence, if the casing 40 is enclosed partially or wholly by the probing portion 41, then the engagement between the casing 40 and the probing portion 41 will be strengthened.
Moreover, the casing 40 suffers from other drawbacks: for example, the casing 40 is made of opaque material and so it is necessary to form an opening 44 on the top of the casing 40 in order for viewing the liquid crystal display 45 of the circuit board inside the casing 40. Moreover, the casing 40 does not have any raised lines for facilitating the holding of the thermometer and is boring in appearance. Furthermore, a resilient packing ring is required to be mounted between the cap and the rear end of the casing 40 in order to prevent water from entering into the casing 40 thus making the manufacturing process complicated and increasing the cost.
In conclusion, as the flexible probing portion 41 is connected only to the front end of the casing 40 and does not enclose the casing 40 and does not have integrally formed raised lines and a water-proof packing ring, the probing portion 41 cannot be firmly engaged with the casing 40 and the manufacturing is made complicated and the cost is increased.
FIG. 4 shows an electronic clinical thermometer according to U.S. Pat. No. 5,165,798. The electronic clinical thermometer has a similar casing 50 and a flexible portion 51 forwardly extended from the casing 50 and terminating in a metal probe 52. However, the electronic clinical thermometer suffers from the same drawbacks as the aforesaid Taiwan Patent Publication No. 495024. Furthermore, the electronic clinical thermometer is very complicated in structure.
FIG. 5 shows an electronic thermometer constructed according to U.S. Pat. No. 6,379,039. The electronic thermometer comprises a casing 60, a probing portion 61 extended from a front end of the casing 60, a connection member 62 provided at the front end of the connection member 62 to hold a metal probe (not shown).
However, the electronic thermometer suffers from the same drawbacks as the Taiwan Patent Publication No. 495024. The connection member 62 is also short in length, and fitted in the interior of the front end of the probing portion 61. After the probing portion 61 has been bent for use in measuring temperatures a number of times, there is a tendency for the connection portion to break Hence, such a thermometer does not have sufficient strength and is not safe in use either. The probing portion 61 is made of soft material and has a rough surface which allows dirt particles to settle into the material and which are difficult to remove.
Referring to FIG. 5 again, the probing portion 61 made of flexible material is connected only to the front end of the casing 60 (which is generally made of hard material) and does not enclose the casing 60 wholly or partially, so that the probing portion 61 is only connected to a portion of the front end of the casing 60. As a consequence, the connection area between the probing portion 61 and the casing 60 is too small to provide a sturdy engagement therefor. Hence, if the casing 60 is enclosed partially or wholly by the probing portion 61, then the engagement between the casing 60 and the probing portion 61 will be strengthened.
Moreover, the casing 60 suffers from other drawbacks: for example, the casing 60 is made of opaque material and so it is necessary to form an opening on the top of the casing 60 in order to view the liquid crystal display. In addition, the casing 60 does not have any raised lines for facilitating the holding of the thermometer and is boring in appearance. Furthermore, a resilient packing ring is required to be mounted between the cap and the rear end of the casing 60 in order to prevent water from entering into the casing 60 thus making the manufacturing process complicated and increasing the cost.
In conclusion, as the flexible probing portion 61 is connected only to the front end of the casing 60 and does not enclose the casing 60 and does not have integrally formed raised lines and a water-proof packing ring, the probing portion 61 cannot be firmly engaged with the casing 60 and the manufacturing is made complicated and the cost is increased.
Furthermore, some conventional electronic thermometers have a flexible push button for a waterproof switch which is a film member (some have an additional switch). Although the push button can deform in the pressing operation, as the deformation of the button is minimal and the switch within the thermometer small, it is necessary to have a rigid key portion provided below the flexible push button for turning on/off the switch when the flexible push button is depressed by the user. The arrangement of the rigid key portion greatly increases the manufacturing cost of the electronic thermometer. Therefore, it is an object of the present invention to provide an improved electronic thermometer which can obviate and mitigate the above-mentioned drawbacks.